From: Toke Høiland-Jørgensen toke@redhat.com
commit d95f1e8b462c4372ac409886070bb8719d8a4d3a upstream.
Turns out the xlated program instructions can also be missing if kptr_restrict sysctl is set. This means that the previous fix to check the jited_prog_insns pointer was insufficient; add another check of the xlated_prog_insns pointer as well.
Fixes: 5b79bcdf0362 ("bpftool: Don't crash on missing jited insns or ksyms") Fixes: cae73f233923 ("bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump()") Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Quentin Monnet quentin@isovalent.com Link: https://lore.kernel.org/bpf/20200206102906.112551-1-toke@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/bpf/bpftool/prog.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -500,7 +500,7 @@ static int do_dump(int argc, char **argv buf = (unsigned char *)(info->jited_prog_insns); member_len = info->jited_prog_len; } else { /* DUMP_XLATED */ - if (info->xlated_prog_len == 0) { + if (info->xlated_prog_len == 0 || !info->xlated_prog_insns) { p_err("error retrieving insn dump: kernel.kptr_restrict set?"); goto err_free; }